0 used to describe paper that measures 8½ inches by 11 inches (= 21.59 cm by 27.94 cm), the standard size of office paper in the US:
For letter-size files arranged front-to-back, the 30- and 42-inch-wide files are the most effective, as the maximum amount of filing per cabinet is enabled.
The typical issue was four letter-size pages sent to subscribers under a second-class mail permit.
The belts could be folded for storage and would fit into an ordinary letter-size envelope.
Rules were not done in booklet form, but on large sheets of paper folded to letter-size as a cost-savings measure.
It also included 512 kilobytes of memory, which was just enough to print graphics at 300 dpi that covered about 70% of the letter-size page area.
